This will be a much more comlicated process than any other Honda front end swap. The DC5 and the EP3 do not have nearly as much in common as the EKs had with the DC2 and the E?s had with each other. More reason to hate the EP3.
Comparing the two bodies:
The bad news:
The wheel arches are in very different spots in relation to the windshield.
Due to this, the character line on the hood is very different.
There is about double the overhang in front of the wheel arch on the DC5 than the EP3.
The door shapes are very different, the A pillars are very similar.
The DC5 is .1 inch wider at the wheel arch, and its hood is .05 inch wider at the wheel arch.
The good news:
The body/chassis attachement point it at the same place on both models, so using the EP's chassis under the EP's body with the new front clip will snap right in place once you've done the body work, and vice versa.
I probably wouldn't suggest this, but if you have to perform this conversion, your best bet would be to cut the cars just through the centerline of the wheel arch (this will go right through the windsheild washer nozzles) and swap the clips there. You will have to do a ton of work blending the fenders, and more to blend the hoods, but this is the only way to do it without absolute major surgery to the kits.